Don't bother sending retractions when we get a request for an unknown prefix.
Don't bother sending retractions when we get a request for an unknown prefix.

Gwendocg/babeldToS,wlanslovenija/babeld,boutier/babeld,wlanslovenija/babeld,jech/babeld,tcatm/babeld,Gwendocg/babeldToS,Drooids/babeld,dtaht/babeld-shortrtt-metrics,sudomesh/babeld,jech/babeld,woniullb/babeld